#install-btn {
  background: #0088cc; /* Old browsers */
  background: -moz-linear-gradient(top, #0088cc 0%, #0055cc 100%); /* FF3.6+ */
  background: -webkit-gradient(
    linear,
    left top,
    left bottom,
    color-stop(0%, #0088cc),
    color-stop(100%, #0055cc)
  ); /* Chrome,Safari4+ */
  background: -webkit-linear-gradient(
    top,
    #0088cc 0%,
    #0055cc 100%
  ); /* Chrome10+,Safari5.1+ */
  background: -o-linear-gradient(
    top,
    #0088cc 0%,
    #0055cc 100%
  ); /* Opera 11.10+ */
  background: -ms-linear-gradient(top, #0088cc 0%, #0055cc 100%); /* IE10+ */
  background: linear-gradient(to bottom, #0088cc 0%, #0055cc 100%); /* W3C */
  filter: progid:DXImageTransform.Microsoft.gradient( startColorstr='#0088cc', endColorstr='#0055cc',GradientType=0 ); /* IE6-9 */

  text-align: center;
  font-size: 200%;
  margin: 1em auto;
  display: block;
  padding: 0.5em;
  color: white;
  width: 10em;
  max-width: 80%;
  line-height: 1.2em;
}
